---
title: 'The Joomla HTTP Headers Plugin'
url: 'https://manuals.remository.com/payage/gateway-paypal-checkout/the-joomla-http-headers-plugin'
markdown: 'https://manuals.remository.com/payage/gateway-paypal-checkout/the-joomla-http-headers-plugin.md'
date: '2026-11-14'
description: 'If you have the Joomla HTTP Headers Plugin enabled with its default settings, the PayPal Checkout popup windows will be blocked. Users will see a blank popup, in some cases with "about:blank#blocked" in the address bar. For PayPal Checkout to work correctly with the Joomla HTTP Headers Plugin enabl…'
taxonomy:
  category:
    - docs
---

[](#) [ edit this page](https://github.com/getgrav/grav-skeleton-rtfm-site/blob/develop/pages/20.gateway-paypal-checkout/02.the-joomla-http-headers-plugin/docs.md) 

# The Joomla HTTP Headers Plugin

If you have the Joomla HTTP Headers Plugin enabled with its default settings, the PayPal Checkout popup windows will be blocked. Users will see a blank popup, in some cases with "about:blank#blocked" in the address bar. For PayPal Checkout to work correctly with the Joomla HTTP Headers Plugin enabled, you will need to set the following options:

| Option | Setting |
|---|---|
| **Referrer-Policy** | strict-origin-when-cross-origin |
| **Cross-Origin-Opener-Policy** | same-origin-allow-popups |

 [ ](https://manuals.remository.com/payage/gateway-paypal-checkout/payage-settings) [](https://manuals.remository.com/payage/gateway-paypal-checkout/paypal-account-settings)

---

## Navigation

- Parent: [Gateway: PayPal Checkout](https://manuals.remository.com/payage/gateway-paypal-checkout.md)
- Previous: [Payage Settings](https://manuals.remository.com/payage/gateway-paypal-checkout/payage-settings.md)
- Next: [PayPal Account Settings](https://manuals.remository.com/payage/gateway-paypal-checkout/paypal-account-settings.md)